Carburetor



y 1942- J. E. STCRER, JR 2,291,418

I I CARBURE'fOR Filed Aug. 21, 1940 f P J6 I J \fd/ire. EJZorer:

Patente d July 28, 1942 CARBURETOR John E. Storer, Jr., Flint, WarnerCorporation,

tion of Illinois Mich., assignor to Borg- Chicago, 111., a corpora-Application August 21, 1940, Serial No. 353,449

1 Claim.

This invention relates to carburetors of the type wherein the idle jettakes its fuel supply from the lower portion of the main nozzle intowhich lower portion the fuel is delivered from the fuel reservoir by apower jet.

In the operation of such a carburetor, there sometimes occurs a hiatusin the delivery of the proper mixture from the carburetor and aconsequent momentary misfiring of the engine, when the throttle is movedfrom a full open position to a position corresponding to a lower speedthan cruising speed, i. e., about half open or slightly less. Where thecarburetor is applied to aircraft, such mis-firing of the engine, eventhough restricted to only one or two cylinders, is particularlyobjectionable.

The general object of the invention is'to improve upon the constructionof the type of carburetor mentioned so as to prevent the occurrence ofthe above described condition. To this end the invention provides meansfor preventing the fuel stream issuing from the power jet from beingprojected past the inlet of the idle jet.

Other objects, the advantages and uses of my invention will become moreapparent after reading the following specification and claim, and afterconsideration of the drawing forming a part of the specification,wherein:

Fig. 1 is an elevation of a carburetor, partly in section, embodying theinvention.

Fig. 2 is a transverse sectional view of the main nozzle taken asindicated by the line 22 of Fig. 1.

Fig. 3 is a detailed sectional view illustrating a modified form of theinvention.

Fig. 4 is a detailed sectional another modification of the invention.

Fig. 5 is a detailed sectional View illustrating a still furthermodification of the invention.

Fig. 6 is a perspective view of another modification of the invention.

Fig. 7 is a perspective view fication of the invention.

Fig. 8 is a sectional View form of the invention.

Fig. 9 is a sectional view of fied form of the invention.

Fig. 10 is a sectional View of a still further modified form of theinvention.

As an illustration of one form in which the invention may be embodied,there is shown in Fig. 1 a carburetor comprising a throttle barrel l2 inwhich is mounted a pair of Venturi tubes l4 and I6 which cooperate withthe barrel l2 to form a fuel mixing passage. Secured to the barrel I2 isa skirt of a further modiof another modified a still further modiviewillustrating I8 through which air flows to the mixture passage. Formedintegral with the skirt [8 is a fuel bowl 20 from which fuel is adaptedto flow through a fuel channel 22 to a power jet indicated generally at24, which is threaded into the wall of the skirt IS in axial alignmentwith the main nozzle 26, which is mounted in a tubular boss 28 formedinside of the skirt I 8.

The lower end of the nozzle 26 is threaded as at 30 into the boss 28 andis provided with a delivery opening 32 through which fuel passes to theidle fuel orifice 34, formed in the lower end of the idle tube 36.

Air is adapted to pass through a nozzle air vent 33 into an annularpassage 38 defined between the main nozzle 26 and the boss 28, and fromthe passage ii] the air may enter the main nozzle 26 through nozzlebleed holes 62 to form, together with the fuel that is being injectedinto the main nozzle by the power nozzle 2%, an emulsion which isdelivered from the main nozzle outlet 44 into the throat of the VenturiIt.

From the vent 38, air may also flow to an annular passage 46 surroundingthe idle nozzle 35, and then through idle vent 48 into the idle tube 36,there to form an emulsion which is delivered through an emulsion channel59'] formed in the wall of the barrel l2 to an idle delivery opening 52,controlled by a needle valve 56.

The flow of air through the mixing passage is controlled by a throttlevalve 58 which when closed is adapted to establish high suction on itsposterior side and to subtantially cut off the flow of air through themixing passage, thereby causing a rich mixture to be drawn from the idleopening 52 into mixing passage posterior of the valve 58. As the valve58 opens, the outlet 5% will become operative to assist the outlet 52 indelivering the rich mixture, and with further opening of the throttle,the fiow of air through the Venturi tubes will increase to a point wherefuel will be delivered from the nozzle outlet M for high speedoperation.

During such high speed or full throttle operation, the demand upon thehigh speed nozzle will be such as to cause a continuous stream of fuelto be projected from the power jet 2! and the idle system will bereversed so that air is drawn from idle fuel orifice 34 into main nozzle26 through delivery opening 32. It has been found that in the high speedoperation of this type of carburetor the stream of fuel from the jet 24was projected beyond the inlet opening 32 of the idle jet, so that upona sudden closing of the throttle from a wide open position, the momentumof the stream would momentarily preforms, comprises simply a pin 60mounted in the 26 and extending diametriso that the stream of lower endof nozzle cally across the mouth,

fuel issuing from the nozzle 24 may impinge thereon and be broken up,this form being illustrated in Fig. 1.

Instead of being mounted on the lower end of nozzle 26, the pin may bemounted in notches in the upper end of the nozzle 24, as indicated inFig. 3, at 69 7 The baffle element may instead of being mounted at rightangles to the axis of the nozzle, be mounted at an angle as shown at601) in Fig. 4.

Instead of taking the form of a pin extending entirely across the nozzlemouth, the bafile element may be secured at one end and extend only partway across the nozzle bore as indicated at 600 in Fig. 5.

The pin 68d shown in mounted in the notches in 24, is mounted in aposition said notches.

Instead of being in the form of a pin, the baffle element may, as shownin Fig. 7, be in the form of a washer 6| having an integral web portionBile extending across the fuel passage.

In the modification of the invention shown in Fig. 8, the baflie isformed by an extension 69] on the end of the idle tube 36F.

In the modification of the invention shown in Fig, 9, the baiile elementis in the form of a separate short tube 60g which comprises the inlet tothe idle passage.

In Fig. 10, the baiiie is likewise in the form of a tube forming theinlet to the idle passage, the tube 60h in this case extending entirelyacross Fig. 6, instead of being the end of the nozzle at right angles tothe nozzle 26 and having an opening 62 through which fuel passes to theidle passage.

Tests have shown that the invention very effectively corrects thedifficulty that has been experienced in connection with the suddenclosing of the throttle after a period of wide open throttle operation.For a long time, the problem remained unsolved until I realized that thecondition was caused by the fuel being thrown past the idle inletopening, and I devised the above dlsclOsed solution to this problem.

While I have described my invention in connection with certainspecific-embodiments thereof, it is to be understood that this is not byway of limitation and that the scope of my invention is defined solelyby the appended claim which should be construed as broadly as the priorart will permit.

I claim:

In a carburetor assembly including means defining a main air passagehaving a venturi therein, a butterfly throttle valve for controlling theflow therethrough and an upwardly extending nozzle having one end incommunication with fuel from a fuel bowl, th other end being positionedwithin said venturi for delivering fuel thereto, said nozzle having astraight cylindrical bore leading from the inlet to th outlet thereof,means defining an idle fuel supply passage having the discharge endthereof under the control of said butterfly valve when moved to the idleposition, said idle passage having an inlet terminal portioncommunicating directly with said nozzle bore at a point spaced along theaxis of said bore from the inlet end thereof, means defining a meteringpower jet located below the inlet. end of said nozzle bore fordelivering fuel from said fuel bowl generally coaxially into said fuelnozzle bore, said arrangement being particularly characterized by theprovision of a pinlike element projecting across the path of flow fromsaid power jet at a point between said power jet defining means and saididle passage inlet, said pin-like element having a cross-sectional arealess than the cross-sectional area of the bore of said nozzle, and beingthe sole obstruction to the free flow of fuel from said jet to theoutlet of said nozzle, said power jet being directed against saidpin-like element which functions to prevent the fuel from beingprojected beyond said idle inlet, thus providing a supply of fuel atsaid idle inlet to be drawn therein when said butterfly valve is movedto idle position to effect a change over from main nozzle feed to idlefeed.

JOHN E. STORER, JR.

